+cf_gnu_xopen_source=$cf_XOPEN_SOURCE
+
+echo "$as_me:3268: checking if this is the GNU C library" >&5
+echo $ECHO_N "checking if this is the GNU C library... $ECHO_C" >&6
+if test "${cf_cv_gnu_library+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+cat >conftest.$ac_ext <<_ACEOF
+#line 3275 "configure"
+#include "confdefs.h"
+#include <sys/types.h>
+int
+main (void)
+{
+
+ #if __GLIBC__ > 0 && __GLIBC_MINOR__ >= 0
+ return 0;
+ #else
+ # error not GNU C library
+ #endif
+ ;
+ return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:3292: \"$ac_compile\"") >&5
+ (eval $ac_compile) 2>&5
+ ac_status=$?
+ echo "$as_me:3295: \$? = $ac_status" >&5
+ (exit $ac_status); } &&
+ { ac_try='test -s conftest.$ac_objext'
+ { (eval echo "$as_me:3298: \"$ac_try\"") >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ echo "$as_me:3301: \$? = $ac_status" >&5
+ (exit $ac_status); }; }; then
+ cf_cv_gnu_library=yes
+else
+ echo "$as_me: failed program was:" >&5
+cat conftest.$ac_ext >&5
+cf_cv_gnu_library=no
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+
+fi
+echo "$as_me:3312: result: $cf_cv_gnu_library" >&5
+echo "${ECHO_T}$cf_cv_gnu_library" >&6
+
+if test x$cf_cv_gnu_library = xyes; then
+
+ # With glibc 2.19 (13 years after this check was begun), _DEFAULT_SOURCE
+ # was changed to help a little...
+ echo "$as_me:3319: checking if _DEFAULT_SOURCE can be used as a basis" >&5
+echo $ECHO_N "checking if _DEFAULT_SOURCE can be used as a basis... $ECHO_C" >&6
+if test "${cf_cv_gnu_library_219+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+ cf_save="$CPPFLAGS"
+ CPPFLAGS="$CPPFLAGS -D_DEFAULT_SOURCE"
+ cat >conftest.$ac_ext <<_ACEOF
+#line 3328 "configure"
+#include "confdefs.h"
+#include <sys/types.h>
+int
+main (void)
+{
+
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 19) || (__GLIBC__ > 2)
+ return 0;
+ #else
+ # error GNU C library __GLIBC__.__GLIBC_MINOR__ is too old
+ #endif
+ ;
+ return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:3345: \"$ac_compile\"") >&5
+ (eval $ac_compile) 2>&5
+ ac_status=$?
+ echo "$as_me:3348: \$? = $ac_status" >&5
+ (exit $ac_status); } &&
+ { ac_try='test -s conftest.$ac_objext'
+ { (eval echo "$as_me:3351: \"$ac_try\"") >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ echo "$as_me:3354: \$? = $ac_status" >&5
+ (exit $ac_status); }; }; then
+ cf_cv_gnu_library_219=yes
+else
+ echo "$as_me: failed program was:" >&5
+cat conftest.$ac_ext >&5
+cf_cv_gnu_library_219=no
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+ CPPFLAGS="$cf_save"
+
+fi
+echo "$as_me:3366: result: $cf_cv_gnu_library_219" >&5
+echo "${ECHO_T}$cf_cv_gnu_library_219" >&6
+
+ if test "x$cf_cv_gnu_library_219" = xyes; then
+ echo "$as_me:3370: checking if _XOPEN_SOURCE=$cf_gnu_xopen_source works with _DEFAULT_SOURCE" >&5
+echo $ECHO_N "checking if _XOPEN_SOURCE=$cf_gnu_xopen_source works with _DEFAULT_SOURCE... $ECHO_C" >&6
+if test "${cf_cv_gnu_dftsrc_219+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+ cf_save="$CPPFLAGS"
+ CPPFLAGS="$CPPFLAGS -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=$cf_gnu_xopen_source"
+ cat >conftest.$ac_ext <<_ACEOF
+#line 3379 "configure"
+#include "confdefs.h"
+
+ #include <limits.h>
+ #include <sys/types.h>
+
+int
+main (void)
+{
+
+ #if (_XOPEN_SOURCE >= $cf_gnu_xopen_source) && (MB_LEN_MAX > 1)
+ return 0;
+ #else
+ # error GNU C library is too old
+ #endif
+ ;
+ return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:3399: \"$ac_compile\"") >&5
+ (eval $ac_compile) 2>&5
+ ac_status=$?
+ echo "$as_me:3402: \$? = $ac_status" >&5
+ (exit $ac_status); } &&
+ { ac_try='test -s conftest.$ac_objext'
+ { (eval echo "$as_me:3405: \"$ac_try\"") >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ echo "$as_me:3408: \$? = $ac_status" >&5
+ (exit $ac_status); }; }; then
+ cf_cv_gnu_dftsrc_219=yes
+else
+ echo "$as_me: failed program was:" >&5
+cat conftest.$ac_ext >&5
+cf_cv_gnu_dftsrc_219=no
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+
+fi
+echo "$as_me:3419: result: $cf_cv_gnu_dftsrc_219" >&5
+echo "${ECHO_T}$cf_cv_gnu_dftsrc_219" >&6
+ test "x$cf_cv_gnu_dftsrc_219" = "xyes" || CPPFLAGS="$cf_save"
+ else
+ cf_cv_gnu_dftsrc_219=maybe
+ fi
+
+ if test "x$cf_cv_gnu_dftsrc_219" != xyes; then
+
+ echo "$as_me:3428: checking if we must define _GNU_SOURCE" >&5